JP2010213243A - Controller and control method used for radio station for radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compensate for defects in the control systems of a centralized control and a decentralized control for a radio resource, to suppress interferences imparted not only to parts among radio stations utilizing the same radio communication system but alto peripheral radio stations, and to effectively utilize a frequency resource. <P>SOLUTION: A controller controlling the propriety of the transmission of the radio station includes an information acquiring part acquiring information displaying the radio communication statuses of other radio stations through a backbone network connected to each radio station. Information displaying the radio communication statuses includes information for frequencies used for other radio stations and the information of the quantities of waveform features displaying the features of the waveforms of radio signals transmitted by other radio stations. The controller has: a waveform information extractor receiving the radio signal and computing the quantities of the waveform features displaying whether signals transmitted from other radio stations are included in the radio signal; and a radio resource parameter determining part determining the propriety of the transmission of the signal from the radio station and determining the radio resource used when the signal is transmitted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radio station control apparatus and control method in an environment in which a plurality of radio stations sharing the same frequency exist.

  In current wireless communication, in many cases, a dedicated frequency band is allocated to each wireless communication system in order to avoid mutual interference. However, in order to effectively use a limited frequency in wireless communication, in recent years, a method of using the same frequency band in a plurality of communication systems has been studied. In order to share the same frequency band with a plurality of radio stations or a plurality of radio communication systems, it is necessary to recognize the usage status of the frequencies and perform transmission control so as not to cause interference. There are two main types of transmission control methods. Each radio station observes the surrounding frequency usage status, and each one autonomously judges whether transmission is possible, and centralized management of the frequency usage status of multiple radio stations. There is centralized control in which a control station that determines whether or not transmission is possible for each wireless station.

  Conventionally, there is a technique for efficiently and repeatedly using the same frequency between different cells in the same system. In a normal cellular system, a technique called frequency repetition between cells is used. In inter-cell frequency repetition, inter-cell interference is avoided by using different frequencies between adjacent cells. In a technique called interference coordination proposed in “3GPP.R1-060670” (Non-Patent Document 1), a radio station at a cell edge is set so that frequencies used at the cell edge are different between adjacent cells. By predetermining the frequency to be assigned to the cell, interference between cells is avoided. Further, in Japanese Patent Application Laid-Open No. 2007-258844 (Patent Document 1), radio stations are grouped on the basis of reports of CQI (Channel Quality Indicator) information from terminals, and resource blocks having different transmission powers are allocated to the cell edges. Techniques for reducing the influence of interference received by radio stations have been proposed. Further, in Patent Document 1, the base station measures the interference power from adjacent cells, and the interference generated by using the same resource block near the cell boundary by changing the power allocated to the same resource block between cells with much interference. Technology to prevent this has also been proposed.

  In Japanese Patent Laid-Open No. 2008-278273 (Patent Document 2), resource allocation information is shared between radio stations in the same system, and allocation is not performed to interference area resources that may cause interference. These technologies share information about the frequency usage status among surrounding radio stations in advance, and determine the resources used by each radio station so that the control station that collected the information does not cause interference. Is the method.

  On the other hand, a carrier sensing multiple access method with a collision avoidance function called CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method is known as a technique for sharing the same frequency in distributed control. This is shown in Non-Patent Document 2, for example. In the CSMA / CA method used in wireless LAN systems represented by the IEEE802.11 standard, the reception level is measured before data transmission to determine whether data transmission is possible. When using the CSMA / CA method as an access method in the same frequency band shared environment by different wireless communication systems, in order to determine whether transmission is possible based on information about the wireless communication environment that each wireless station independently collects, Even without sharing information between systems, each wireless station can avoid interference by transmitting only when no signal is detected.

  Further, in Japanese Patent Laid-Open No. 2006-222665 (Patent Document 3), the presence of a signal is detected by calculating the periodic steadiness feature amount of the signal, and each radio station performs transmission only when no signal is detected. Techniques for avoiding interference are shown. By using this technology, even when sharing the same frequency band between different wireless communication systems, the presence of signals used in the surroundings is detected, and if it is determined that interference does not occur, the wireless station performs transmission It becomes possible.

JP 2007-258844 A JP 2008-278273 A JP 2006-222665 A Japanese Patent Application Laid-Open No. 2008-0621214

3GPP.R1-060670 Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, ANSI / IEEE Std 802.11, 1999 Edition Matsuda, Takiguchi, Ariki, "Speech interval detection using third-order cumulant speech features," IEICE Technical Report Vol.106, No.263 (20060919) pp.37-42 IEEE 802.22 Working Group of the LAN MAN Standards Committee, "IEEE P802.22 / D0.1 Draft Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Policies and procedures for operation in the TV bands ", The Institute of Electrical and Electronics Engineers, May 2006.

  When the same frequency band is shared between a plurality of different wireless communication systems, it is considered that information cannot always be exchanged between wireless stations. When centralized control of radio resources is performed, signal quality may be significantly degraded if such information is lacking. Specifically, in the method of Non-Patent Document 1 of the prior art, users are distinguished by spreading codes and share the same frequency, but information such as spreading codes is used between radio stations using different radio communication systems. It is not always possible and interference cannot always be avoided. In addition, in the method of suppressing interference by interference coordination for a radio station at the cell edge, it is possible that a precise cell design may not be possible depending on the assumed frequency sharing environment, and an area where characteristic degradation may occur due to interference may occur. It is done. Furthermore, in the method of Patent Document 1 of the prior art, the base station groups mobile stations based on the report of CQI information from the mobile stations, and allocates resources for each group. Since radio stations using different radio communication systems cannot share CQI information by radio signals, such grouping and appropriate resource allocation may be difficult. Similarly, in the method of Patent Document 2, it is conceivable that the resource allocation information cannot be shared in the assumed environment, so that the resource that can avoid the interference cannot be specified, and the characteristics are significantly deteriorated. As described above, the centralized control method is complicated in that it requires a lot of information, and it is difficult to share information between systems such as the same frequency band sharing environment between different wireless communication systems. There is a problem that the characteristics are significantly deteriorated under the conditions.

  On the other hand, in distributed control using the conventional CSMA / CA method or the method disclosed in Patent Document 3, the determination of whether or not transmission is possible by each wireless station is not always optimal. For example, communication is actually being performed around a certain radio station, and the radio station should refrain from transmission, but independently determines that radio resources are free for some reason, and the radio station There is a risk of using resources and causing interference. On the other hand, it is also possible that the radio station determines that the radio resource is being used due to erroneous detection and refrains from transmission even though the radio resource is not used by surrounding radio stations. In this case, interference does not occur, but frequency utilization efficiency decreases. In this way, distributed control can avoid interference even in situations where information sharing is insufficient compared to centralized control, and the processing complexity is low, but the effect of interference avoidance and frequency utilization efficiency are inferior to centralized control. Conceivable.

  The present invention is intended to compensate for the disadvantages of both centralized control and distributed control methods, and suppresses interference not only between wireless stations using the same wireless communication system but also surrounding wireless stations, and the frequency. It is an object of the present invention to provide a control device and a control method for effectively using resources.

  In the present invention, a control apparatus in a radio station connected to a backbone network, which is information about radio communication status used by surrounding radio stations through the backbone network, at least frequency band usage status information, An information acquisition unit that acquires information including feature amount information relating to a waveform of a signal to which a frequency band is assigned; and the feature amount that is obtained in the information acquisition unit by receiving a radio signal transmitted by the surrounding radio station A waveform information extraction unit that calculates a waveform feature amount of the received signal based on the information, and self-radio communication based on the waveform feature amount calculated in the frequency band usage status information, the feature amount information, and the waveform information extraction unit Radio resource parameter determining unit for determining parameters of radio resources used in the system and whether or not data transmission is possible , The controller having a, to achieve the above object. In particular, in a frequency sharing environment in which a plurality of radio stations and a counterpart radio station share the same frequency band, it is possible to realize communication that does not interfere with each other.

  The present invention is a control apparatus in a radio station connected to a backbone network, which is information on radio communication status used by surrounding radio stations through the backbone network, and includes at least frequency band usage status information, An information acquisition unit that acquires information including feature amount information relating to a waveform of a signal to which a frequency band is assigned; a radio signal transmitted by the surrounding radio station; the received signal is demodulated; and a demodulated data symbol A signal demodulator that outputs a sequence; a waveform information extractor that calculates a waveform feature of the received signal based on the feature information obtained by the information acquisition unit; and a reliability determination of the demodulated data symbol sequence A reliability determination unit, the frequency band usage status information, the demodulated data symbol sequence, the reliability, the feature amount information, and the waveform information A radio resource parameter determining unit which determines a parameter and whether data transmission using radio resources in the radio communication system based on the waveform feature amount calculated in the extraction unit can also be configured as a control device having a.

  By connecting to the backbone network, this control device can acquire information on the wireless communication status used by the surrounding wireless stations, and therefore is a signal of a wireless station using a different wireless communication system. However, it is possible to detect the presence and magnitude of the signal level by calculating the waveform feature amount.

  In the control device, the radio resource parameter determination unit rejects transmission when the waveform feature amount obtained from the waveform information extraction unit exceeds a preset threshold, thereby suppressing interference with surrounding radio stations. It becomes possible.

  This control apparatus includes a quality estimation table in which the peak size of the waveform feature amount and the channel quality are associated with each other in the radio resource parameter determination unit, and the peak of the waveform information amount obtained in the waveform information extraction unit. Based on the size, the channel quality with the surrounding radio stations is estimated, and the radio resource parameters used in the own radio communication system and the availability of data transmission are determined based on the estimation result. Wireless resources can be effectively used while suppressing interference.

  The control apparatus includes a reliability determination unit that determines the reliability of the demodulated data symbol sequence, and determines whether the demodulated data symbol sequence output from the signal demodulating unit is used for radio resource parameter determination. It can be judged from sex.

  The radio resource parameter determination unit discards the demodulated data symbol sequence when the reliability of the demodulated data symbol sequence is equal to or less than a threshold, and the frequency band usage status information, the feature amount information, and the waveform information extraction unit Signals of surrounding radio stations can be used even in a poor communication environment in which demodulation is impossible by determining parameters of radio resources used in the radio communication system and whether data transmission is possible based only on the calculated waveform feature amount. Can be detected and radio resources can be used effectively while suppressing interference.

  The radio resource parameter determination unit includes an interference estimation unit that estimates an amount of interference given to the surrounding radio stations based on information obtained from the demodulated data symbol sequence, and the reliability of the demodulated data symbol sequence is equal to or higher than a threshold value. In some cases, if signals of surrounding wireless stations can be demodulated by determining whether to use radio resource parameters and data transmission in the own radio communication system based on the estimation result of the amount of interference given to the radio station, It is possible to use the radio resources effectively while preferentially using the information obtained from the data and suppressing interference with the surrounding radio stations.

  The control device further includes a bandpass filter unit that passes only a specific band component of the input signal and blocks other components, receives a signal transmitted by a surrounding radio station, and receives the signal for the received signal. By using a signal that is band-limited based on the use frequency band information acquired by the information acquisition unit as the reception signal, more accurate signal detection can be performed.

  The bandpass filter unit is a frequency allocated to a signal determined to be using a part or all of its own desired transmission band from the frequency band usage status information acquired by the information acquisition unit. A signal transmitted by a surrounding wireless station may be received using the band as a pass band, and the band of the received signal may be limited.

  The band pass filter unit may receive a signal transmitted by a surrounding wireless station and limit the band of the received signal based on a desired transmission band.

  The present invention relates to a control method in a radio station connected to a backbone network, which is information on radio communication status used by surrounding radio stations through the backbone network, and includes at least frequency band usage status information, An information acquisition step for acquiring information including feature amount information related to a waveform of a signal to which a frequency band is assigned; and the feature amount obtained in the information acquisition step by receiving a radio signal transmitted by the surrounding radio station Waveform information extraction step for calculating the waveform feature amount of the received signal based on the information, and self-radio communication based on the waveform feature amount calculated in the frequency band usage status information, the feature amount information, and the waveform information extraction step Wireless resources used in the system and parameters that determine whether data transmission is possible And over scan parameter determination step it can also be configured as a control method having a.

  The present invention relates to a control method in a radio station connected to a backbone network, which is information on radio communication status used by surrounding radio stations through the backbone network, and includes at least frequency band usage status information, An information acquisition step for acquiring information including feature amount information relating to a waveform of a signal to which a frequency band is assigned; a radio signal transmitted by the surrounding radio station is received; the received signal is demodulated; and a demodulated data symbol A signal demodulation step for outputting a sequence, a waveform information extraction step for calculating a waveform feature amount of the received signal based on the feature amount information obtained in the information acquisition step, and a data symbol sequence obtained in the signal demodulation step A reliability determination step for determining the reliability of the frequency band usage status information, the demodulation Radio resource parameter determination for determining whether or not data transmission is possible and parameters of radio resources used in the own radio communication system based on the waveform feature quantity calculated in the data symbol string, the reliability, the feature quantity information, and the waveform feature extraction step And a control method including steps.

  As described above, according to the present invention, regardless of the radio communication system used by the surrounding radio stations, the radio station effectively uses radio resources while suppressing interference given to the surrounding radio stations. Frequency utilization efficiency can be improved.

1 is a schematic diagram of a wireless communication system. The block diagram which shows the radio station by 1st Example of this invention. The block diagram which shows the control apparatus of the radio station by 1st Example of this invention. The figure for demonstrating an example of a waveform feature-value. The figure which shows an example of the radio | wireless communication status information in 1st Example of this invention. The flowchart which showed the control procedure in the radio | wireless resource parameter determination part of a control apparatus. The block diagram of the control apparatus in the radio station by the modification 1.1 of this invention. The flowchart which showed the control procedure in the radio | wireless resource parameter determination part of the control apparatus by the modification 1.1 of this invention. The block diagram of the control apparatus in the radio station by the modification 1.2 of this invention. The figure which shows the passband setting example (a) of the band pass filter part in the modification 1.2 of this invention. The figure which shows the passband setting example (b) of the band pass filter part in the modification 1.2 of this invention. The figure which shows the passband setting example (c) of the bandpass filter part in the modification 1.2 of this invention. The conceptual diagram of the example of a radio | wireless resource sharing environment in case a certain base station is equipped with the control apparatus. The conceptual diagram of the example of radio | wireless resource sharing environment in case the control apparatus is provided in both base stations. The conceptual diagram of the example of a radio | wireless resource sharing environment in case the mobile station is equipped with the control apparatus. The block diagram of the control apparatus in the radio station by 2nd Example of this invention. The block diagram of the radio station which comprises the control apparatus by 2nd Example of this invention. The flowchart which showed the control procedure in the radio | wireless resource parameter determination part of a control apparatus. The block diagram of the control apparatus in the radio station by the modification 2.1 of this invention. The flowchart which showed the control procedure in the radio | wireless resource parameter determination part of the control apparatus by the modification 2.1 of this invention. The block diagram of the control apparatus in the radio station by the modification 2.2 of this invention. The block diagram of the control apparatus in the radio station by the modification 2.3 of this invention.

  Examples of the present invention will be described from the following viewpoints.

First Embodiment System Radio Station and Control Device Waveform Feature Quantity Operation Modification 1.1
Modification 1.2
Modification 1.3
Second Embodiment Radio Station and Control Device Operation Modification 2.1
Modification 2.2
Modification 2.3

<System>
FIG. 1 shows a schematic diagram of a wireless communication system. The wireless communication system includes a plurality of base stations 1101 and 1102 and mobile stations 1103 and 1104. For convenience of explanation, it is assumed that the communication partner of the mobile station 1104 is one of the mobile stations 1103. Base stations 1101 and 1102 may belong to the same radio system or may belong to different radio systems. However, the base stations 1101 and 1102 are configured such that information on other radio stations (base stations or mobile stations) can be obtained as necessary. In the illustrated example, the base stations 1101 and 1102 are connected to the backbone network 109 and can acquire information of other wireless stations.

  In the backbone network 109, there may be an information management server that centrally manages information and returns necessary information in response to an information acquisition request from a wireless station. Alternatively, the base stations may be directly connected to each other and exchange information without using such an information management server.

  Although described as “mobile station” in the figure, an apparatus that communicates with a base station may be not only a mobile station but also a fixed station.

<Radio station and control device>
FIG. 2A is a block diagram of the radio station 11 according to the first embodiment of the present invention. The radio station 11 includes a control device 10, an antenna 104, a transmission / reception separation unit 105, a parameter control unit 106, a modulation unit 107, and a signal generation unit 108, and is connected to a backbone network 109. A signal input to the antenna 104 of the radio station 11 is input to the control device 10 via the transmission / reception separating unit 105. Based on the analysis result information of the received signal and the radio communication status information acquired from the backbone network, the control device 10 determines whether or not to transmit the signal, and if it can be transmitted, the radio device used when transmitting the signal Determine parameters. The determined radio resource parameters (parameters indicating data modulation scheme, frequency resource block, transmission power, etc.) are given to parameter control section 106.

  The transmission data of the radio station 11 is modulated by the modulation unit 107 and converted into a radio signal by the signal generation unit 108. It will be obvious to those skilled in the art that not only modulation but also processing such as encoding and interleaving is performed. The transmission signal generated according to the parameter from the parameter control unit 106 is transmitted from the antenna 104 through the transmission / reception separating unit 105 and delivered to the counterpart radio station that is the communication partner of the radio station 11.

  FIG. 2B shows details of the control apparatus 10 of the radio station of FIG. 2A. The control device 10 includes an information acquisition unit 101, a waveform information extraction unit 102, and a radio resource parameter determination unit 103.

  The information acquisition unit 101 is connected to the backbone network 109, and the connection method may be variously set such as use of a wired transmission path or use of a wireless transmission path. A backbone network is a network that can exchange information held by radio stations connected to the backbone network. The information acquisition unit 101 acquires wireless communication status information related to surrounding wireless stations via the backbone network 109. The wireless communication status information is information including at least frequency usage status information and feature amount information of signals used by surrounding wireless stations, and also includes reception quality information, communication traffic information, and the like in surrounding wireless stations. Also good.

  The waveform information extraction unit 102 calculates the waveform feature amount of the input signal based on the feature amount information of the signal used by the surrounding wireless stations obtained by the information acquisition unit 101.

  FIG. 3 shows an example of wireless communication status information. The frequency usage status information is information indicating the frequency usage status in the surrounding radio stations, and is information indicating the frequency usage status at the time of the waveform feature amount extraction operation in the waveform information extraction unit 102 and thereafter at a certain time. is there. The signal feature amount information indicates the waveform feature amount of a signal that is actually transmitted at a frequency in use in the frequency use status information. The waveform feature amount is information relating to statistical characteristics of the signal waveform, and periodic stationarity obtained by a secondary periodic autocorrelation value, a signal amplitude dispersion value, a frequency correlation value, or the like may be used. . Further, past information may be used by storing the frequency use status information and the signal feature amount information in a storage device separately prepared in the radio station or the control device. The feature amount information will be described later.

  The radio resource parameter determination unit 103 in FIG. 2B determines whether data transmission is possible and the parameters of the radio resource to be used based on the radio communication status information obtained from the information acquisition unit 101 and the waveform feature quantity obtained from the waveform information extraction unit 102. The determination content is notified to the parameter control unit 106 in FIG. 2A. Examples of the radio resource parameters determined by the radio resource parameter determination unit 103 include a center frequency, a bandwidth, transmission power, a modulation scheme, a coding scheme, and the like. A specific parameter determination method will be described later.

<Waveform features>
The signal waveform is determined by various parameters such as the center frequency, frequency bandwidth, transmission power, modulation scheme, transmission information symbol, etc. Conversely, the signal waveform has the characteristics of the above parameters. include. For example, in the case of the above-mentioned Patent Document 3, a technique for calculating the periodic autocorrelation value of a signal and detecting the presence / absence of the signal from the characteristic value of the periodic steadiness of the signal is shown. In this case, the characteristic that the value of the periodic autocorrelation value of the signal becomes large only when a parameter specific to the calculation of the periodic autocorrelation value is used according to the modulation method used for the signal is used. ing. Further, Patent Document 4 proposes a means for imparting different periodic steadiness feature amounts to signals using the same modulation method. These are merely examples, and feature quantities representing features of signal waveforms can be expressed from various viewpoints such as signal correlation values and statistical values.

  FIG. 2C is a diagram for describing a periodic steadiness feature value generated by the influence of a filter as an example of a signal feature value. (1) in FIG. 2C represents a frequency spectrum of a signal having a bandwidth B [Hz] subjected to band limitation using an ideal filter. When an ideal filter is used, the frequency spectrum can be rectangular, but in practice it is difficult to achieve such a steep spectrum, so a filter with a moderate frequency spectrum is usually used for band limitation. Used for. (2) in FIG. 7 represents a frequency spectrum when band limitation is performed using a normal realistic filter. As shown in (2) of FIG. 7, compared with the case where an ideal filter is used, a frequency band is broadened in a band limiting filter that is normally used. In this widened frequency band, the region indicated by P spread on the right side has the same signal component as the region indicated by P ′ on the left side, and the region indicated by Q ′ spread on the left side is the Q region on the right side. Have the same signal component. Therefore, the portion P ′ in the signal (3) obtained by frequency shifting the signal (2) in FIG. 2C by B [Hz] has the same signal component as P in (2), and the portion Q ′ in (3) is ( Since it has the same signal component as Q in 2), a high correlation value is brought about.

  In this way, the signal band-limited by the filter has a correlation (periodic autocorrelation) between the original signal and the signal obtained by frequency shifting the original signal. This correlation value becomes the feature quantity of the waveform. In the illustrated example, the correlation between a certain signal and a signal obtained by shifting the signal in the frequency direction has been considered, but it is also conceivable that the signal is similarly shifted in the time direction. In the present embodiment, such a correlation value is used to detect whether a received system signal is included in the received signal.

  Using the techniques of conventional Patent Document 3 and Patent Document 4, the control device of the present invention can calculate the waveform feature amount included in the received signal. That is, when a surrounding radio station is transmitting a signal having a characteristic value of a certain periodic steadiness, the radio station equipped with the control device of the present invention is unique to the calculation of the cyclic autocorrelation value through the backbone network. The information regarding the parameters is acquired, and the periodic autocorrelation value of the received signal is calculated using the acquired unique parameters. When the signal is included, the value of the periodic autocorrelation value is a large value exceeding the threshold value. When the signal is not included or included at a negligible level, the value of the periodic autocorrelation value is Since the threshold value is not exceeded, the signal can be detected. In general, feature detection using signal waveform information such as periodic steady-state feature quantities is more sensitive to noise power in the received signal than signal detection based on received power used in the conventional CSMA / CA. This is performed with high accuracy even when the power is small. Furthermore, when a surrounding wireless station transmits a signal, it emphasizes and adds a feature quantity of a specific periodic stationarity, thereby improving the detection system, capturing the feature quantity itself as information, and different wireless communication systems. It is considered that direct communication can be performed between wireless stations.

  In addition to the periodic stationarity derived by calculating the correlation value between a signal and a signal obtained by shifting the signal in any direction, the signal amplitude variance, that is, two values, can be used as a statistic that can be used as a waveform feature. There is a second order cumulant. In general, the second order cumulant corresponds to the variance of the possible values of the amplitude. For example, the value of the secondary cumulant is greatly different between a signal having a very high peak power to average power ratio (PAPR) such as an OFDM signal and a constant envelope signal or noise such as a single carrier signal. Since the former takes various amplitude values, the dispersion is large, and the dispersion of the latter is relatively small. By utilizing such a property, it is possible to detect whether an OFDM signal is included in the received signal. For example, as the feature amount information of the secondary cumulant value of the signal, the time variation characteristic of the secondary cumulant value in the transmission signal of the surrounding radio station is acquired by the information acquisition unit 101 of the control device 10, and this is used as the threshold value. Is set. Comparing the time variation characteristic of the value of the secondary cumulant calculated by the waveform feature quantity extraction unit 102 with the threshold, it can be determined that there is a signal if it is higher than the threshold, and that there is no signal if it is lower than the threshold. The signal can be detected. Similarly to the case of periodic stationarity, when a surrounding radio station transmits a signal, the characteristic amount of a specific secondary cumulant is added to the signal and transmitted (the amplitude dispersion becomes a predetermined value). In this way, it is possible to intentionally control the amplitude), to improve the detection accuracy, to capture the feature quantity itself as information, and to exchange information directly between radio stations of different radio communication systems.

  As a statistic that can be used as a waveform feature amount in addition to the periodic steadiness and the second-order cumulant, a frequency correlation characteristic of a signal can be used as well (Non-Patent Document 4). In the case of frequency correlation characteristics, a bias of signal power is given to the subcarrier frequency component of a multicarrier signal such as OFDM, and a radio station equipped with the control device of the present invention calculates the frequency correlation value of the received signal, The peak value, the number of peaks, the frequency interval between a plurality of peaks, and the like can be detected as a waveform feature amount.

  As described above, the waveform feature amount representing the feature of the signal waveform may be based on the correlation value of the signal or may be based on a statistical value such as variance.

<Operation>
FIG. 4 is a flowchart showing a control procedure in the radio resource parameter determination unit of the control device 10. First, the wireless communication status information of surrounding wireless stations is acquired from the information acquisition unit 101 of FIG. 1 (S401), and within the desired transmission band of the wireless station 11 itself from the frequency band usage status information included in the wireless communication status information. Then, it is checked whether or not a band used by surrounding wireless stations is allocated (S402). If not allocated, it is determined that the band can be used for data transmission of the own device (S404).

  Here, the desired transmission band is a frequency band that the wireless station 11 desires to use in communication with a counterparty radio station as a communication partner. For example, a signal transmitted by itself in a transmission path to the counterparty radio station is greater than a predetermined value. This is the frequency band when the frequency band that is received by power and the frequency band that can be used are limited by the hardware and regulations of the wireless station 11. The desired transmission band can be set as a frequency bandwidth that can achieve a desired communication capacity in a frequency band that can be used by the radio station 11 in hardware. In this case, the frequency bandwidth is One continuous frequency band may be requested, or a plurality of frequency bands may be used simultaneously to request a set of these frequency bands when a desired communication capacity can be achieved.

  If there is any assignment in the band in step S402, the feature amount information of the received signal calculated in the waveform information extraction unit 102 is acquired (S403), and the feature amount level of the calculation result is compared with a threshold value (S405). When the feature amount level exceeds the threshold value, it is determined that data transmission is not permitted (S406).

  For example, it is assumed that the base station 1101 of FIG. 1 includes the control device 10 and the control device 10 is analyzing a signal of another radio station 1102. The control device 10 calculates the feature amount level of the signal transmitted from the base station 1102. When the feature amount level is large, the radio signal from the radio station 1102 reaches the radio station 1101 efficiently. This means that when the radio station 1101 transmits a signal in that band, it causes a large interference with the communication of the other radio station 1102. For this reason, when the feature amount level exceeds the threshold value in step S405, the band is not used for data transmission of the wireless station 1101. On the other hand, if the feature amount level does not exceed the threshold value, data transmission is permitted and a transmission parameter to be used is determined (S404).

  The feature amount information is information in which the waveform information extraction unit 102 aggregates the calculation results of feature amounts obtained periodically or for a predetermined time before this control. When determining the transmission parameters to be used, the amount of transmission data transmitted from the wireless station 11 to the counterparty radio station, the channel characteristics between the radio station 11 and the counterparty radio station, and the like are also taken into consideration. Specifically, the usable frequency band and time are determined according to the above control procedure, and the transmission power, modulation scheme, encoding scheme, and the like are determined so that a desired transmission data rate can be obtained. In addition, as described above, when the wireless communication status information includes reception quality information and communication traffic information in surrounding wireless stations, the transmission power, modulation method, coding method, etc. are also taken into account. Determine.

  As described above, in the first embodiment, even when a plurality of wireless communication systems cannot communicate with each other, the wireless communication system is recognized and transmitted by utilizing the waveform feature amount of the signal used in each wireless communication system. Each radio station autonomously determines a radio resource to be used so that a signal to be interfered does not interfere. As a result, radio resources that can be used increase and frequency utilization efficiency can be improved compared to a distributed control method that does not provide sufficient information about signals without complicated control as much as centralized control.

<Modification 1.1>
FIG. 5 shows a control device 10 according to a first modification of the first embodiment. The radio resource parameter determination unit 103 further includes a quality estimation table 110. It is not essential for the present invention that the quality estimation table 110 is prepared in the radio resource parameter determination unit 103, and the quality estimation table 110 may be prepared anywhere inside or outside the apparatus. However, from the viewpoint of using the information of the quality estimation table 110 in the radio resource parameter determination unit 103, it is desirable that the quality estimation table 110 is prepared in the radio resource parameter determination unit 103 as illustrated.

  The quality estimation table 110 stores the correspondence between the waveform feature value output from the waveform information extraction unit 102 and the channel quality between the wireless station 11 and surrounding wireless stations. When the calculation result of the waveform feature amount is input from the waveform information extraction unit 102, the radio resource parameter determination unit 103 refers to the quality estimation table 110 that is held in advance, and the radio station 11 and the signal having the waveform feature amount Estimate the quality of the communication path with the surrounding wireless station that is the transmission source.

  FIG. 6 is a flowchart of a control procedure performed by the radio resource parameter determination unit in the first modification. For convenience of explanation, it is assumed that the present control apparatus 10 is prepared in the radio station (base station) 1101 of FIG. 1 and the signals of other radio stations 1102 are analyzed. First, the control device 10 in FIG. 5 acquires the wireless communication status information of the surrounding wireless stations 1102 from the information acquisition unit 101 (S601). From the frequency band usage status information included in the radio communication status information, it is checked whether or not a band used by the surrounding radio station 1102 is allocated within a frequency band that can be transmitted by the radio station 1101 itself (S602). If there is no allocation within the band, it is determined to allow data transmission (S604). In step S602, if there is any assignment in the band, the feature amount information calculated in the waveform information extraction unit 102 is acquired (S603), and the feature amount level of the calculation result is compared with the threshold value (S605). If the feature amount level exceeds the threshold value, it is determined that data transmission is not permitted (S606).

If the feature amount level does not exceed the threshold value, the flow proceeds to step S607. In step S607, when the own station 1101 transmits a signal, it is estimated using the feature amount level and quality estimation table 110 whether or not the other station 1102 is greatly provided. In this example, the quality estimation table 110 manages the channel quality (for example, CQI) between the own station 1101 and the other station 1102 for each radio station. The signal transmitted by each radio station can be determined by some feature amount information. The number of other stations is not necessarily one, and there may be any number. In the case of FIG. 1, 1103 may be added to other stations. In any case, in step S607, when the local station 1101 transmits a signal based on the quality of the signal received by the local station 1101 from the other station 1102, the amount of interference reaching the other station 1102 is estimated. Whether the wireless station 11 (1101 in the present example) can achieve a desired communication quality, for example, a desired data rate, etc. under a transmission power limit that can suppress the interference to a predetermined level or less. It is determined whether or not (S608). If it is determined that the desired communication quality cannot be achieved, it is determined that data transmission is not permitted (S606). If it is determined that the desired communication quality can be achieved, data transmission is permitted and transmission parameters to be used are determined under the above restrictions (S604).
The threshold value used in step S605 of the first modified example can be a larger value than the threshold value used in step S405 of FIG. As apparent from FIGS. 4 and 6, when the threshold value to be compared with the feature amount level is small, the flow easily proceeds to steps S406 and S606, and the wireless station 1101 becomes difficult to transmit a signal. On the other hand, when the threshold is large, the flow easily proceeds to steps S404 and S607, and an opportunity to transmit a signal to the wireless station 1101 is easily provided. In this modification, after confirming the presence / absence of a signal from another station (S605), it is determined whether or not transmission from the own station is possible from the viewpoint of reception quality. Therefore, the flow in FIG. 6 is preferable from the viewpoint of increasing opportunities for transmission than in the case of FIG. Even if there is a certain amount of signals from other stations, interference with other stations can be reduced by flexibly controlling parameters such as transmission power according to the channel characteristics between the local station and other stations. can do. Thereby, a communication opportunity can be increased and frequency utilization efficiency can be improved.

<Modification 1.2>
FIG. 7 shows a control device 10 according to a second modification 1.2 of the first embodiment. In the present control device, a band pass filter unit 111 is provided before the waveform information extraction unit 102.

  The signal input to the antenna 104 of the radio station 11 is input to the bandpass filter unit 111 through the transmission / reception separating unit 105, and the band is limited. Band limitation is processing in which the frequency components in the pass band of the input signal are passed as they are and other frequency components are not passed. The bandpass filter unit 111 may be prepared exclusively for this control, or may be shared with a noise removal filter used for normal wireless communication.

  FIG. 8 schematically shows how band limitation is performed by the bandpass filter unit 111. As described above, the information acquisition unit 101 acquires information related to the frequency usage status of surrounding wireless stations. Based on this frequency usage information, for example, as in the passband setting example (a) of FIG. 8, the passband of the radio station is set to the frequency band used by the surrounding radio stations. The band-limited signal is input to the waveform information extraction unit 102, and by calculating the waveform feature value, the influence of unnecessary waves and noise components outside the band of the signal to be calculated can be removed. Is calculated more accurately. Furthermore, by performing the same calculation for all signals that may exist in the vicinity, a large amount of information can be obtained, and highly accurate resource control can be performed.

  As shown in the passband setting example (b) of FIG. 9, the bandpass filter unit 111 may set the passband differently from the case of FIG. In the case of FIG. 9, the use frequency band of a radio station that uses part or all of the desired transmission band of the radio station (for example, the base station 1101) itself that includes the control device 10 among the surrounding radio stations is the pass band. May be set. Specifically, in the example of FIG. 9, since the signals b and c of the peripheral wireless stations are included in the desired transmission band, these signals are allowed to pass, and the other signals (the signals a of the peripheral wireless stations) are Blocked. In such a band limitation process, the waveform feature amount can be calculated only for transmission signals of surrounding wireless stations that have an influence on the desired transmission band. Therefore, the calculation amount can be reduced more than the band limitation in FIG. Is possible. In addition, by ignoring signals outside the desired transmission band, signals in a band that is significantly different from the band are not considered, and feature quantity calculation and resource control suitable for the frequency band in which the signal is actually transmitted are possible. Become.

  As shown in the passband setting example (c) of FIG. 10, the bandpass filter unit 111 may set the desired transmission band of the radio station 11 provided with the control device 10 as the passband as it is. In such band limiting processing, the waveform feature amount can be calculated only for signals that exist within the desired transmission band, and therefore, when there is a signal for which information has not been obtained in advance, Even when the signal is shifted to a band different from the band obtained from the frequency usage status information due to the influence of the offset or the like, the waveform feature amount can be calculated. In this case, if the characteristics of the filter used for transmission / reception of the radio station 11 match, the bandpass filter unit 111 in the control device can be used for normal transmission / reception, and vice versa. The filter can also be used as a bandpass filter unit in the control device.

<Modification 1.3>
The radio station 11 described in FIG. 2A may be a base station or a mobile station. The control device 10 is provided in the radio station 11. Therefore, the control device 10 according to the present embodiment may be provided in the base station or in the mobile station.

  FIG. 11 shows an example in which a control device is provided only in a certain base station 1101. However, the control device 10 can acquire information (frequency information and waveform feature amount information) of other stations as needed via the backbone network 109. The base station 1101 acquires information on the wireless communication status of the base station 1102 and the mobile station 1103 that is a communication partner of the base station 1102 connected through the backbone network 109. The base station 1101 calculates the waveform feature amount of the signal transmitted from the base station 1102 or the mobile station 1103 using the acquired information on the wireless communication status, and the base station 1101 transmits to the other mobile station 1104. At this time, when it is determined that interference is caused to the base station 1102 or the mobile station 1103, transmission to the mobile station 1104 of the other party is not performed. If it is determined that no significant interference occurs even if transmission is performed, parameters of radio resources to be used are determined, and transmission to the mobile station 1104 of the other party is started.

  As described above, by using this embodiment, the base station 1101 accurately recognizes the surrounding wireless communication status, and when interference does not occur, the resources used by the base station 1102 and the mobile station 1103 are utilized to move the other party. Since communication with the station 1104 can be performed, the use efficiency of radio resources can be improved, and at the same time, the occurrence of interference can be avoided efficiently.

  FIG. 12 shows an example of a radio resource sharing environment different from FIG. 11 is generally the same as the case of FIG. 11, except that the own station and the other stations are provided with the control device 10 in the case of FIG. Each of a plurality of wireless stations that can exchange information with each other in the backbone network 109 includes the control device 10 according to the present embodiment. As a result, each radio station can determine the presence / absence of signals from other stations and can avoid interference, thereby further improving the efficiency of radio resources.

  FIG. 13 shows still another example of a radio resource sharing environment. 11 and 12, the base station is provided with a control device, but in FIG. 13, the control device 10 is provided in the mobile station. However, the control device 10 needs to acquire information on other stations, and the information is acquired via the base station 1301 connected to the backbone network using a wireless communication path. The operation of the control device is the same as the already described flowcharts (FIGS. 4 and 6). When the mobile station 1304 including the control device 10 of the present invention performs such processing, it is possible to further reduce the influence of interference that the radio wave transmitted from the mobile station 1304 has on the surrounding base station 1302 and the mobile station 1303. It becomes possible. For example, when an adapter that can be connected to the backbone network is connected to a mobile station, even the mobile station can be connected to the backbone network, improving the use efficiency of radio resources in communication with the base station that is the communication partner. However, it can be expected that the occurrence of interference can be avoided.

  Note that the examples shown in FIGS. 11, 12, and 13 are not alternative, and the control device 10 may be prepared in one or more radio stations.

<Radio station and control device>
FIG. 14 is a block diagram of the radio station 21 according to the second embodiment of the present invention. The radio station 21 includes a control device 20, an antenna 204, a transmission / reception separation unit 205, a parameter control unit 206, a modulation unit 207, and a signal generation unit 208, and is connected to the backbone network 209. A signal input to the antenna 204 of the radio station 21 is input to the control device 20 via the transmission / reception separating unit 205. The control device 20 determines whether or not to transmit a signal based on the analysis result information of the received signal and the wireless communication status information acquired from the backbone network, and if it can be transmitted, the radio resource used when transmitting the signal Determine parameters. The determined radio resource parameters (parameters indicating data modulation scheme, frequency resource block, transmission power, etc.) are given to parameter control section 206.

  The transmission data of the radio station 21 is modulated by the modulation unit 207 and converted into a radio signal by the signal generation unit 208. It will be obvious to those skilled in the art that not only modulation but also processing such as encoding and interleaving is performed. The transmission signal generated according to the parameter from the parameter control unit 206 is transmitted from the antenna 204 through the transmission / reception separating unit 205 and delivered to the counterpart radio station that is the communication counterpart of the radio station 21.

  FIG. 15 shows details of the control device 20 of the radio station of FIG. The control device 20 includes an information acquisition unit 201, a waveform information extraction unit 202, a radio resource parameter determination unit 203, a signal demodulation unit 212, and a reliability determination unit 213. Although the interference estimation unit 214 is depicted as being included in the radio resource parameter determination unit 203, this is not essential to the present invention, and the interference estimation unit 214 is located anywhere inside or outside the control device 20. It may be provided.

  The information acquisition unit 201 is connected to the backbone network 209, and the connection method may be variously set such as use of a wired transmission path or use of a wireless transmission path. A backbone network is a network that can exchange information held by radio stations connected to the backbone network. The information acquisition unit 201 acquires wireless communication status information related to surrounding wireless stations via the backbone network 209. In the case of the second embodiment, the wireless communication status information includes information necessary for demodulating the signals communicated by the surrounding wireless stations, in addition to the frequency usage status information and the feature amount information of the signals used by the surrounding wireless stations. Is also included. More specifically, information necessary for demodulating a signal communicated by surrounding wireless stations may be specified by parameters such as a data modulation scheme, a channel coding scheme, a frequency band (resource block), and the like. . Similarly to the first embodiment, the wireless communication status information may include reception quality information, communication traffic information, and the like in surrounding wireless stations.

  The waveform information extraction unit 202 calculates the waveform feature amount of the input signal based on the feature amount information of the signal used by the surrounding wireless stations obtained by the information acquisition unit 201.

  Radio resource parameter determination section 203 determines whether or not data transmission is possible and the parameters of radio resources to be used, based on the radio communication status information obtained from information acquisition section 201 and the waveform feature quantity obtained from waveform information extraction section 202. The determination content is notified to the parameter control unit 206 in FIG. Examples of the radio resource parameters determined by the radio resource parameter determination unit 203 include a center frequency, a bandwidth, transmission power, a modulation scheme, a coding scheme, and the like.

  The signal demodulation unit 212 performs demodulation processing on the received signal input to the antenna 204 of the radio station 21 using information necessary for demodulation of the signal derived from the information acquisition unit 201. At this time, the demodulated signal is input to reliability determination section 213, the reliability level of the demodulation result is calculated, and the result is input to radio resource parameter determination section 203. For example, the calculation of the reliability level is obtained using the detection result based on the error detection code, the decoding error rate of a known symbol included in the received signal, and the like. Although not essential, a high reliability level means that the signal-to-noise ratio SNR is high when a signal received from another station is the signal component S. Therefore, when the reliability level measured for a signal received from another station is high, there is a possibility that interference will be caused to the other station if the signal is transmitted without limit from the own station. In this case, signal transmission is permitted after some interference avoidance measures are taken.

  In the radio resource parameter determination unit 203, the interference estimation unit 214 estimates the interference to be given to surrounding radio stations when the reliability determination result in the reliability determination unit 213 is equal to or greater than a threshold value. The interference can be estimated based on information on the wireless communication status obtained from the information acquisition unit 201 and information included in the demodulation result obtained from the signal demodulation unit 212. The radio resource parameter determination unit 203 is configured so that radio resource parameters (e.g., antenna weight, transmission power, center frequency, bandwidth, transmission power, modulation scheme, encoding scheme, etc.) are reduced so that the interference with neighboring radio stations is reduced. ).

  When the radio resource parameter determination unit 203 determines that the reliability level is higher than the threshold and the demodulation process can be performed correctly, the radio resource parameter determination unit 203 determines whether or not radio resource parameters and data transmission are possible based on the interference estimation result. When the radio resource parameter determination unit 203 determines that the reliability level is lower than the threshold value and the demodulation process is not performed correctly, the radio resource parameter determination unit 203 discards the demodulation result and based on the waveform feature amount obtained from the waveform feature amount extraction unit 202 Determine the parameters of radio resources to be used and whether data transmission is possible.

<Operation>
FIG. 16 is a flowchart showing a control procedure in the radio resource parameter determination unit 203 of the control device 20. First, the information acquisition unit 201 in FIG. 15 acquires wireless communication status information of surrounding wireless stations (S1601). The radio resource parameter determination unit 203 checks whether or not the band used by the surrounding radio stations is allocated within the desired transmission band of the radio station 21 from the frequency band use status information included in the radio communication status information ( In S1602), if there is no allocation in the band, it is determined to permit data transmission (S1608).

  As shown in FIG. 15, the received signal is input to the signal demodulator 212 and demodulated. Information on how to demodulate (data modulation scheme, channel coding rate, frequency band, etc.) is provided from the information acquisition unit 201. The reliability determination unit 213 determines the reliability of the demodulation result. In step S1602 of FIG. 16, when it is determined that there is some allocation in the band, the reliability determination result (calculated reliability level) is compared with a threshold (S1604).

  When the reliability level exceeds the threshold value, there is a possibility of causing interference to other stations if a signal is transmitted from the own station without limitation. In this case, signal transmission is permitted after some interference avoidance measures are taken. If no countermeasures can be taken, signal transmission is prohibited. In the case of the illustrated example, the radio resource parameter determination unit 203 acquires information on a demodulation result from the signal demodulation unit 212 (S1605), and determines whether interference can be avoided (S1606). When it is determined that interference avoidance is impossible, data transmission is disallowed (S1607). When it is determined that interference avoidance is possible, data transmission is permitted and transmission parameters to be used are determined. (S1608).

  If the reliability level of the demodulation result does not exceed the threshold value in step S1604, the signal received from the other station does not reach the local station well. In this case, the demodulated signal is discarded because the signal received and demodulated by the local station is not suitable as a criterion for determining whether or not to transmit the signal by the local station. As in the first embodiment, whether or not the signal transmission of the own station is possible is determined based on the waveform feature amount. If the reliability level of the demodulation result does not exceed the threshold value in step S1604, the radio resource parameter determination unit 203 acquires the calculation result (feature amount level) of the waveform feature amount of the received signal by the waveform information extraction unit 202 (S1609). ). The acquired feature amount level is compared with the threshold (S1610), and if the feature amount level exceeds the threshold, data transmission is not permitted (S1607), and if the feature amount level does not exceed the threshold, data transmission is performed. Is determined and transmission parameters to be used are determined (S1608).

  Note that the reliability determination result, the demodulation result, and the waveform feature amount calculation result may be sequentially acquired from each unit as in the flow of FIG. 16, or all information may be obtained before the processing illustrated in the flow of FIG. May be stored in a memory separately prepared in the present control device, and information may be extracted from the memory as necessary.

  In the second embodiment, transmission may be permitted not only when the feature level is high (NO in step S1610) but also when the reliability level of the demodulated signal is high (YES in S1604). There is. Information based on the waveform feature amount can be acquired even in a low reception SNR environment as in the first embodiment, and more information can be acquired based on a demodulation result in a higher reception SNR environment. Here, when a certain radio station (for example, 1101) receives a signal with a high SNR, it is considered that extremely large interference occurs for the radio station (for example, 1102) that is the transmission source of the signal. . However, by using information obtained as a result of demodulation, interference with the radio station can be suppressed to a sufficiently low level using, for example, transmission beam control or high-accuracy transmission power control. In this case, it is possible to obtain a communication opportunity and to achieve high frequency utilization efficiency.

  Further, in this embodiment, it is possible to take a form in which the interference estimation unit 214 is not used. Even in this case, more detailed information than the information based on the waveform feature can be obtained by using the demodulation result, so it is possible to collect information with high accuracy in information collection that is performed for a certain period of time or periodically before this control. Thus, it is possible to perform radio resource control with higher reliability than in the first embodiment.

<Modification 2.1>
FIG. 17 shows a control device 20 according to a first modification of the second embodiment. Similarly to the modification 1.1 of the first embodiment, the radio resource parameter determination unit 203 includes a quality estimation table 210.

  The quality estimation table 210 associates the value of the waveform feature amount output from the waveform information extraction unit 202 with the communication channel quality between the radio station 21 and the surrounding radio stations. When receiving the calculation result of the waveform feature amount from the waveform information extraction unit 202, the radio resource parameter determination unit 203 refers to the quality estimation table 210, and communicates the channel quality between the radio station 21 and the surrounding radio stations. Is estimated.

  FIG. 18 is a flowchart showing a control procedure of the control device 20 according to this modification. First, the information acquisition unit 201 in FIG. 17 acquires wireless communication status information of surrounding wireless stations (S1801). The radio resource parameter determination unit 203 checks whether the band used by the surrounding radio stations is allocated within the desired transmission band of the radio station 11 from the frequency band use status information included in the radio communication status information (S1802 If there is no allocation within the band, it is determined to permit data transmission (S1808). When there is an allocation within the band, the radio resource parameter determination unit 203 acquires a reliability determination result (reliability level) (S1803), and compares the reliability level of the demodulation result with a threshold (S1804). When the reliability level exceeds the threshold value, the radio resource parameter determination unit 203 acquires the demodulation result information from the signal demodulation unit 212 (S1805), and determines whether the interference estimation unit 214 can avoid interference. (S1806). If it is determined that interference avoidance is impossible, data transmission is not permitted (S1807), and if it is determined that interference avoidance is possible, a transmission parameter to be used for allowing data transmission is determined. (S1808).

  If the reliability level of the demodulation result does not exceed the threshold value in step S1804, the demodulation result is discarded and the calculation result of the waveform feature amount of the received signal is used as in the first embodiment (S1809). The radio resource parameter determination unit 203 compares the acquired feature amount level with a threshold value (S1810). When the feature amount level does not exceed the threshold value, the channel quality between the own station and the other station is estimated from the feature amount level using the quality estimation table 210 as in the first modification, The amount of interference that the local station may have on other stations is estimated (S1811). As a result, the radio resource parameter determination unit 203 determines whether or not a desired communication quality, such as a desired data rate, can be achieved under a transmission power limit that can suppress the interference to a predetermined level or less. (S1812). When it is determined that the desired communication quality cannot be achieved, it is determined that data transmission is not permitted (S1807), and when it is determined that the desired communication quality can be achieved, data transmission is permitted, A transmission parameter to be used under the above restriction is determined (S1808). Note that the reliability determination result, the demodulation result, and the waveform feature amount calculation result may be sequentially acquired from each unit as in the flow of FIG. 18, or all information may be obtained before the processing illustrated in the flow of FIG. 18. The information may be stored in a memory separately prepared in the control apparatus, the information used according to the flow is determined, and the determined information is taken out from the memory and used.

  In the present modification 2.1, as in the modification 1.1, when the reliability of the demodulation result is equal to or lower than the threshold value and the feature amount level is equal to or higher than a certain level, communication between the surrounding wireless station and the wireless station 21 is performed. It is possible to flexibly control parameters such as transmission power according to the path characteristics, and to transmit signals within the range of interference power that does not affect the surrounding wireless communication, increasing communication opportunities and improving frequency utilization efficiency. Can be increased.

<Modification 2.2>
FIG. 19 shows a block diagram of a control device 20 according to a second modification 2.2 of the second embodiment. In the present modification, as in the modification 1.2 shown in FIG. 7, the signal input to the antenna 204 of the radio station 21 is input to the bandpass filter unit 211 of the control device 20 through the transmission / reception separating unit 205, and the band is limited. The The band-pass filter unit 211 may be prepared exclusively for this control, or may be shared with a noise removal filter used for normal wireless communication. The bandpass filter unit 211 sets the frequency band used by the surrounding radio stations as the passband based on the frequency use status information obtained in the information acquisition unit 201 as in the passband setting example (a) of FIG. . The band-limited signal is input to the waveform information extraction unit 202 and the signal demodulation unit 212, and waveform feature amount calculation and demodulation processing are performed. As a result, the influence of unnecessary waves and noise components outside the band of the signal to be calculated can be removed, so that the calculation of the waveform feature amount and the demodulation process are performed more accurately. Furthermore, by performing the same calculation for all signals that may exist in the vicinity, a large amount of information can be obtained, and highly accurate resource control can be performed.

  As shown in the passband setting example (b) of FIG. 9, the bandpass filter unit 211 is based on the frequency usage status information from the information acquisition unit 201, and among the surrounding radio stations, A use frequency band of a radio station that uses a part or all of the part may be used as a pass band. Specifically, in the example of FIG. 9, since the signals b and c of the peripheral wireless stations are included in the desired transmission band, these signals are passed and other signals (the signals a of the peripheral wireless stations) are passed. Cut off. In such band limiting processing, the calculation and demodulation processing of the waveform feature amount can be performed only for the transmission signals of the surrounding wireless stations that have an influence on the desired transmission band. It becomes possible to reduce. In addition, by ignoring signals outside the desired transmission band, signals in a band that is significantly different from the band are not considered, and feature amount calculation, demodulation processing, and resource control suitable for the frequency band in which the signal is actually transmitted Is possible.

  As shown in the passband setting example (c) of FIG. 10, the bandpass filter unit 211 may be implemented with the desired transmission band of the own station 21 itself as the passband. In such band limiting processing, waveform feature amount calculation and demodulation processing can be performed only for signals existing in the desired transmission band. Therefore, even when a signal for which information has not been obtained in advance exists in the band, or when the signal is shifted to a band different from the band obtained from the frequency usage status information due to the influence of frequency offset, etc., the waveform characteristics Quantity calculation and demodulation processing can be performed. In this case, if the characteristics of the filter used for transmission / reception of the radio station 21 match, the band-pass filter unit 211 in the control device can be used for normal transmission / reception, and vice versa. The filter can also be used as a bandpass filter unit in the control device.

  The above-mentioned modifications 1.1 and 1.2, and 2.1 and 2.2 can be combined, respectively. For example, the control device 10 may be constructed in which the modification examples 1.1 and 1.2 in the first embodiment are combined, the radio resource parameter determination unit 103 includes the quality estimation table 110, and further includes the bandpass filter unit 111. With such a configuration, the control device of the first embodiment performs the calculation of the waveform feature amount more accurately, and even between the surrounding wireless stations and the wireless station 11 even when the feature amount level falls below the threshold value. It is possible to flexibly control parameters such as transmission power according to the communication path characteristics.

<Modification 2.3>
Similarly, the modification examples 2.1 and 2.2 in the second embodiment can be combined. As a third modification 2.3 of the present embodiment, a control device 20 that combines modifications 2.1 and 2.2 will be described.

  FIG. 20 shows a block diagram of a control device according to the third modification 2.3 of the second embodiment. The control device includes a quality estimation table 210 and a bandpass filter unit 211.

  In Modified Example 2.3, as in Modified Example 2.1, when the reliability of the demodulation result is equal to or lower than the threshold value and the feature amount level is equal to or higher than a certain level, the communication path characteristics between the own station and the other station are changed. Accordingly, the radio parameters are flexibly controlled. As a result, it is possible to transmit a signal from the own station while taking into consideration that interference does not reach other stations in the vicinity, increasing communication opportunities and improving frequency utilization efficiency. Similarly to the second modification 2.2, the influence of unnecessary waves and noise components outside the band of the signal to be calculated can be removed by the bandpass filter unit 211, so that the calculation of the waveform feature amount and the demodulation process can be further performed. Exactly done.

  Although the present invention has been described with reference to particular embodiments, they are merely exemplary and those skilled in the art will appreciate various variations, modifications, alternatives, substitutions, and the like. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. Although specific mathematical formulas have been used to facilitate understanding of the invention, these mathematical formulas are merely examples, unless otherwise specified, and any appropriate mathematical formula may be used. The division of the embodiment or item is not essential to the present invention, and the matters described in two or more embodiments or items may be used in combination as necessary, or may be described in a certain embodiment or item. Matters may apply to matters described in other examples or items (unless they conflict). For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be realized by hardware, software, or a combination thereof. The software may be provided on any suitable storage medium such as random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, etc. . The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

10, 20 Control device 11, 21 Radio station 101, 201 Information acquisition unit 102, 202 Waveform information extraction unit 103, 203 Radio resource parameter determination unit 104, 204 Antenna 105, 205 Transmit / receive separation unit 106, 206 Parameter control unit 107, 207 Modulation unit 108, 208 Signal generation unit 109, 209 Backbone network 110, 210 Quality estimation table 111, 211 Band pass filter unit 212 Signal demodulation unit 213 Reliability determination unit 214 Interference estimation unit 1101, 1102, 1201, 1202, 1301 1302 Base stations 1103, 1104, 1203, 1204, 1303, 1304 Mobile stations

Claims (18)

A control device that controls whether a wireless station can transmit in a wireless communication system,
An information acquisition unit that acquires information indicating a radio communication status of another radio station different from the radio station through a backbone network connected to the radio station and the other radio station, and indicating the radio communication status The information includes information on a frequency used by the other radio station and information on a waveform feature amount indicating a waveform characteristic of a radio signal transmitted by the other radio station,
A waveform feature amount indicating whether or not a signal transmitted from the other wireless station is included in the wireless signal is received based on the information on the waveform feature amount. A waveform information extraction unit to calculate;
Based on the frequency information, the waveform feature amount information, and the waveform feature amount calculated by the waveform information extraction unit, it is determined whether or not to transmit a signal from the radio station, and is used when transmitting a signal. A radio resource parameter determination unit for determining radio resources to be
Control device. A control device for controlling whether or not a wireless station can transmit in a wireless communication system,
An information acquisition unit that acquires information indicating a radio communication status of another radio station different from the radio station through a backbone network connected to the radio station and the other radio station, and indicating the radio communication status The information includes information on a frequency used by the other radio station, and information on a waveform feature amount indicating a waveform characteristic of a radio signal transmitted by the other radio station,
A waveform feature amount indicating whether or not a signal transmitted from the other wireless station is included in the wireless signal is received based on the information on the waveform feature amount. A waveform information extraction unit to calculate;
A signal demodulator that receives and demodulates a radio signal and outputs a demodulated data symbol sequence;
A reliability determination unit that determines the reliability of the demodulated data symbol sequence;
Based on the information on the frequency, the information on the waveform feature amount, the waveform feature amount calculated in the waveform information extraction unit, the demodulated data symbol sequence, and the reliability, whether or not a signal can be transmitted from the radio station A radio resource parameter determining unit that determines radio resources to be used when transmitting a signal,
Control device.   The radio resource parameter determination unit determines that the desired transmission frequency band is used by the other radio station based on the frequency information, and if the waveform feature value calculation result exceeds a threshold, data The control device according to claim 1, wherein transmission is prohibited. The radio resource parameter determination unit
A table for quality estimation that correlates the peak size of the waveform feature quantity with the signal quality in the communication path between the radio station and the other radio station;
Based on the waveform information amount calculated by the waveform information extraction unit, the signal quality in the communication path is estimated, the radio transmission station determines whether signal transmission from the radio station is possible and transmits radio signals. 4. The control device according to claim 1, wherein the controller is determined.   The radio resource parameter determination unit discards the demodulated data symbol sequence when the reliability of the demodulated data symbol sequence is equal to or lower than a threshold, and the frequency information, the waveform feature amount information, and the The control device according to claim 2, wherein, based on the waveform feature amount calculated by the waveform information extraction unit, whether to transmit a signal from the radio station is determined, and a radio resource used when transmitting the signal is determined. . The radio resource parameter determination unit includes an interference estimation unit that estimates an amount of interference given to the other radio station based on the demodulated data symbol sequence,
When the reliability of the demodulated data symbol sequence is equal to or higher than a threshold, whether to transmit a signal from the radio station is determined based on the estimation result of the amount of interference given to the other radio station, and the signal is transmitted. 6. The control apparatus according to claim 2, wherein a radio resource to be used is determined. The control device further includes a band-pass filter unit that passes a specific band component of the received radio signal and blocks other components,
The control device according to claim 1, wherein the control device receives a radio signal and performs band limitation based on the frequency information acquired by the information acquisition unit.   8. The bandpass filter unit according to claim 7, wherein the bandpass filter unit performs band limitation using a frequency band including a transmission desired band of the wireless station as a pass band based on the frequency information acquired by the information acquisition unit. The control device described.   The control device according to claim 8, wherein the band-pass filter unit performs band limitation in a band that matches a transmission desired band of the radio station. A control method for controlling whether or not a radio station can transmit in a radio communication system,
An information acquisition step of acquiring information indicating a wireless communication status of another wireless station different from the wireless station through a backbone network connected to the wireless station and the other wireless station, and indicating the wireless communication status The information includes an information acquisition step including information on a frequency used by the other radio station and information on a waveform feature amount indicating a waveform characteristic of a radio signal transmitted by the other radio station;
A waveform feature amount indicating whether or not a signal transmitted from the other wireless station is included in the wireless signal is received based on the information on the waveform feature amount. A waveform information extraction step to be calculated;
Based on the frequency information, the waveform feature amount information, and the waveform feature amount calculated in the waveform information extraction step, it is determined whether or not to transmit a signal from the radio station, and is used when transmitting a signal. A radio resource parameter determination step for determining a radio resource to be
A control method. A control method for controlling whether or not a radio station can transmit in a radio communication system,
An information acquisition step of acquiring information indicating a wireless communication status of another wireless station different from the wireless station through a backbone network connected to the wireless station and the other wireless station, and indicating the wireless communication status The information includes an information acquisition step including information on a frequency used by the other radio station and information on a waveform feature amount indicating a waveform characteristic of a radio signal transmitted by the other radio station;
A waveform feature amount indicating whether or not a signal transmitted from the other wireless station is included in the wireless signal is received based on the information on the waveform feature amount. A waveform information extraction step to be calculated;
A signal demodulation step of receiving and demodulating a radio signal and outputting a demodulated data symbol sequence;
A reliability determination step of determining the reliability of the demodulated data symbol sequence;
Based on the information on the frequency, the information on the waveform feature amount, the waveform feature amount calculated in the waveform information extraction step, the demodulated data symbol sequence, and the reliability, whether or not a signal can be transmitted from the radio station A radio resource parameter determining step for determining radio resources to be used when transmitting a signal;
A control method.   The radio resource parameter determination step determines that the desired transmission frequency band is used by the other radio station based on the frequency information, and if the calculation result of the waveform feature amount exceeds a threshold, data The control method according to claim 10 or 11, wherein transmission is prohibited. The radio resource parameter determination step includes:
Using a quality estimation table that correlates the peak size of the waveform feature amount with the signal quality in the communication path between the wireless station and the other wireless station,
Based on the waveform information amount calculated in the waveform information extraction step, the radio resources used when estimating the signal quality in the communication path, determining whether or not to transmit a signal from the radio station, and transmitting the signal 13. The control method according to claim 10, wherein the control method is determined.   The radio resource parameter determination step discards the demodulated data symbol sequence when the reliability of the demodulated data symbol sequence is equal to or less than a threshold, and the frequency information, the waveform feature amount information, and the 12. The control method according to claim 11, wherein whether or not to transmit a signal from the radio station is determined based on the waveform feature amount calculated in the waveform information extracting step, and a radio resource used when transmitting the signal is determined. . The radio resource parameter determination step estimates the amount of interference given to the other radio station from the demodulated data symbol sequence,
When the reliability of the demodulated data symbol sequence is equal to or higher than a threshold, whether to transmit a signal from the radio station is determined based on the estimation result of the amount of interference given to the other radio station, and the signal is transmitted. 15. The control method according to claim 11 or 14, wherein a radio resource to be used is determined. The control method further includes a step of performing band limitation using a bandpass filter that passes a specific band component of a received radio signal and blocks other components,
The control method according to claim 10 or 11, wherein a radio signal is received and band limitation is performed based on the frequency information acquired in the information acquisition step.   17. The step of performing band limitation performs band limitation using a frequency band including a desired transmission band of the radio station as a pass band, based on the frequency information acquired in the information acquisition step. The control method described in 1.   The control method according to claim 16, wherein the step of performing band limitation performs band limitation in a band that matches a transmission desired band of the wireless station.

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